Structure and Phase Regulation in MoxC (α-MoC1-x/β-Mo2C) to Enhance Hydrogen Evolution

Highlights

Monodisperse inverse opal-like MoxC nanospheres were synthesized.

The structure and phase of MoxC can be controlled by changing the amount of SiO2.

There is a strong synergistic effect between α-MoC1-x and β-Mo2C.

The optimal MoxC exhibited a superior HER performance and excellent stability.

Abstract

Non-precious metal-based efficient electrocatalysts with superior activity and stability for the hydrogen evolution reaction (HER) are useful in solving energy and environmental crises. Herein, monodisperse inverse opal-like MoxC (α-MoC1-x/β-Mo2C) nanospheres were synthesized via a facile strategy to adjust the intrinsic activity and maximize the exposed active sites. In particular, the MoxC-0.4 with the optimal composition of α-MoC1-x/β-Mo2C (0.56/0.44) demonstrated a superior HER performance in 0.5 M H2SO4 with a small Tafel slope of 48 mV dec-1 and remarkable stability. Such prominent performance not only benefits from the inverse opal-like structure that provides more active sites for HER, but also should be ascribed to the strong synergistic effect between α-MoC1-x and β-Mo2C. Based on theoretical calculations, it is further verified that the synergistic effect of MoxC-0.4 is originated from the optimization of interaction with the H* induced by the heterostructure. Furthermore, this work will broaden our vision for highly efficient hydrogen production by bridging the microscopic structure with macroscopic catalytic performance.

Keywords

Molybdenum carbide
electrochemical catalyst
hydrogen evolution reaction
heterostructure